Rinse water conditioner and process



UNiTED STATES PATENT @FFHCE RINSE WATER CONDITIONER AND PROCESS John F. Littooy, San Francisco, Calif., assignor to Hercules Glue Company, San Francisco, Calif., a corporation of California N Drawing. Application May 15, 1929, Serial No. 363,404

4 Claims. (01. 146219) In fruit packing plants it is universally the drops, which under average temperature condipractice to wash such fruit as apples, usually tions and with free circulation of air require an in an acid washing solution, to remove spray hour or more to dry. Particularly is it difficult residue. The fruit is then rinsed, after it has to dry the stem and calyx ends, where capilbeen removed from the washing solution, in lary force tends to hold the moisture against supposedly clear water (actually this becomes all attempts to remove it by mechanical, pneuacidulated through acid solution carried over by matic, or thermal means. Inasmuch as about the apples from the Washing tank), andis dethree minutes, or less, are required to move the livered to the sorting tables and to the packing fruit from the rinse tank to the packing bins, bins. Between the rinse tankand the packing it is clear that means and a method must be 65 binspreferably between the rinse tank and the provided whereby the moisture may ordinarily sorting tablesthe apples must be dried, for and regularly be removed in three minutes or they cannot dry properly as they lie in closely less.

J packed masses in the packing bins, because air The various disadvantages, discomforts, and

does not circulate freely about them. It is also losses touched on above have heretofore been highly inconvenient, and to some degree dangertreated as unavoidable and incident to the busious to the sorters and packers if the fruit is not ness, but I have discovered how the fruit may dried before it reaches them. Any concentrabe placed in condition for drying under natural tion of acid or soluble arsenic compounds (which conditions and at normal temperatures in about F 30 is sometimes found because of the use of alkali a minute'or less, especially Where forced air draft 5 water) in the stem or calyx ends, and beneath is employed, thus eliminating all such losses and the sepals, promotes injury to the fruit and imdiscomforts, through a process of conditioning pairs its keeping qualities, yet this cannot be the rinse water, into which the fruit is dipped removed by drying agencies heretofore emafter its removal from the washing solution, to

ployed, Wet r moist apples, if e e slightly lower its surface tension and to cause it to form bruised or punctured, as occurs in their h a persisting film of substantially uniform thickdling 01 temporary storage, will absorb the m0is IlQSS CV81 the surface of the fruit, rather than ture, and Whether the moisture be acid or Collecting in p in the d D S S- W 1th arsenic-bearing, or reasonably pure, the co di rinse Water thus conditioned not only is there 30 t and keeping qualities of th apples are a larger wet surface area continually exposed to versely affected. Chemicals picked up from the drying agancies, but e is a tendency to mainapples on the hands or gloves of Sorters and tain the film intact, and to replace Water which packers W111 quickly prove injurious y t these has been evaporated or removed from the more workers must change gloves, under conditions exposed areas With Water d awn y Capillary 35 obtaining heretofore, very frequently, to allow traction (due 'P the DQ593199 of minute 90 them to dry and some must Wear rubber gloves closely spaced solid particles which are deposited to protet themselves from injury as the film dries) from the reservoirs in the It may be that the apples would dry if given depresgwnsi and 3 beneath the sepale sufficient time and were spaced to provide free There 15 thus a P drawmg movmg of 40 air circulation, but it is not economically possithe Water from me mctect'ed areas Water m to employ as much Space as would be traps to the exposed areas, from whence it can quired for this purpose, and furthermore, d with facility be removed or evaporated. Results age W111 result to the fruit in many cases if the have shown that apples which under er o acid or arsenic is left to concentrate for theditions could not be dried inside of an hour, are

time required for natural drying. To preserve dried with the assistance of my conditioner in the fruit from damage it must be dried quickly, not to exceed one minuteless than the time and yet it has not been possible heretofore to requi d place'the pp in the hands of t dry the fruit quickly and thoroughly enough sorter after leaving the rinse tank. Packers by any known methods. It is to the solution of a Sorters WhO formerly Changed l v every directed. now use a single pair all day, and find them I have discovered that the reason why apples scarcely damp at night.

do not dry quickly, after rinsing, is because the Not only is it possible to accelerate the drying,

high surface tension of the rinse water causes but it is possible at the same time to neutralize the water to collect and cling to the fruit in the acid condition of the rinse water, occasioned 110 this problem that my present invention is few minutes, to permit the wet gloves to dry,

'ticularly caseinbeing highly effective.

by some of the washing solution being carried over on the fruit, and thus to forestall the possibility of acid burns and rotting. This, however, is a subsidiary feature of my invention or discovery, which relates, in the main, to a substance for conditioning the rinse water, as specifically distinguished. from the washing solution, to the improved rinse solution itself, and to the process of preparing the rinse water and 0f rinsing the fruit.

The features which I consider as being of the essence of my invention or discovery will be pointed out in this specification, and will be particularly defined by the claims terminating the same.

As has been mentioned above, the rinse water ordinarly used to remove the acidulous washing solution from the fruit is intended as pure water, though it is usually tinged with acid, or carries in solution soluble arsenic compounds. This water or slightly acid solution tends to gather in drops, which present large volumes (as compared to the capacity of the drying agencies employed) with small surface areas, and the drying agencies, acting over the entire surface of the fruit, cannot be sufiiciently concentrated on these random drops, or on the collections in the depressions, in the limited time permitted them to act, to remove the water completely. In order to spread the drops over larger areas, thus to expose the water more uniformly to the drying agencies, I add to the rinse water a substance which lowers its surface tension, and which gives to it a tendency to spread as a film, and to maintain that film of uniform thickness, drawing from the depressions to compensate for a deficiency on the more exposed areas.

Various substances may be employed as a conditioner to achieve this effect, proteinspar When arsenic compounds are the chief components of the spray residue, all alkali-soluble protein-contain ng substances, such as casein, albumens, soya bean meal, peanut meal, etc., may be employed, as well as other substances including some carbohydrates, soluble resinates, etc., all of which are colloid-forming materials tending to lower the surface tension of the rinse water. These are given as illustrations, rather than as limitations, and as many substances of this general character will operate satisfactorily, naturally I do not wish to be limited, in the broader aspects of my invention, or as relates to the process, to the use of any given substance. However, certain substances have the advantages of cheapness, availability, or better effectiveness, and I shall therefore proceed to describe one substance which gives particularly valuable results, being also comparatively cheap and readily available, as illustrative of the principle of my discovery.

Casein is particularly eifective, and while it would be satisfactory alone, its cost, used in the quantities necessary, might run the cost of the rinsing higher than the packer desires to pay. As a complemental dispersing or film-forming agent, and as a means of increasing the uniformity of the film formed on the fruit, I use powdered rosin or dextrin, a carbohydrate, or a mixture or" the two. Soda ash, in small quantitles, may be adcd as an accelerator to disperse or dissolve the casein and rosin or dextrin in the rinse Water, though obviously its inclusion is ptuely a convenience. As a vehicle and filler for the other ingredients, and as a neutralizing to considerable variations.

agent for acid in the rinse water, I may use calcium hydrate (hydrated lime). It may be omitted, so far as a conditioner, or aid to drying. For the latter purpose only such a colloid as casein or rosin or dextrin need be employed, these agents acting much alike, but the rosin or dextrin may replace part of the more expensive but more efficient and desirable casein or other protein.

The proportions of the ingredients are subject Of casein or its protein equivalent (ground dried and defatted beef or horse-meat, milk or blood, albumen, etc.) I use from 8 to 20%. Of soda ash or its equivalents (sodium bicarbonate or trisodium phosphate) some 2% or less is sufiicient. Rosin or clextrin should not ordinarily exceed 8% of the whole, though even small quantities, 1% or less, are beneficial, though these require larger percentages of the more expensive casein. The calcium hydrate (Ca (OI-D2) is employed as a filler, to complete the whole. Thus, a satisfactory mixture, from the standpoint of effectiveness and cost, contains the ingredients in the following proportions:

Per cent Casein 16 Powdered rosin or dextrin 5 Soda ash 2 Calcium hydrate 77 This mixture is a powder from which is made a creamy fluid which is either mixed into the rinse tank in the proportion of one pound of dry powder to 100 gallons of water, or, if the rinse water is wasted away and renewed, the fluid is permitted to drip into the rinse water at the rate of one pound of powder to each fresh 100 gallons of water.

Fruit rinsed in water so conditioned will not permit the water to collect in drops, but such water as clings to the fruit will spread as a film over its surface. The fruit is then subjected to drying agents, as wiping cloths, jets or blasts of heated air, etc., and as water is removed from the exposed portions of the fruit it is replaced by water drawn from the protected portions, tending to restore and equalize the film, until finally the film is reduced to negligible thickness. During this action the water is drawn from the depressions at the stem and calyx ends, from beneath and around the sepals, and from minute abrasions, and as a result all deleterious substances are withdrawn, or spread so thinly that no damage to the fruit can occur from such sources.

What I claim as my invention is:

l. A process of rinsing acid treated fruit for packing which comprises subjecting the fruit to the action of a colloidal solution of casein, and then subjecting the fruit for a period of short duration to drying conditions during which the colloidal solutions tends to become evenly distributed over the surface of the fruit and dries rapidly.

2. A process of rinsing acid treated fruit for packing which comprises subjecting the fruit to the action of a colloidal solution of casein con- 4. A process of rinsing fruit for packing, for employment, after the fruit has been Washed, comprising subjecting the fruit to the action of a protein-bearing colloidal solution, and next subjecting the fruit for a period of short duration to drying conditions during which the colloidal solution tends to become evenly distributed over the surface of the fruit and dries rapidly.

JOHN F. LITTOOY. 

